Hi all,
I have enabled desktop effects of Kwin to have transparent panels. Currently I am using Keramik as window theme. My system is an openSUSE 11.2 with KDE 4.3.4 release 2 installed using KDE4 repositories.

My problem is that also window buttons (like close and minimize) are transparent; more precisely, the black part (i.e., the x of close and _ of minimize) is trasparent while other parts of the button is ok. If I choose a different window theme, like Plastik, such buttons are no more transparent. I think the problem is due to the color of the transparent part: in Keramik, the color is a pure black (#000000) while in Plastik is a very dark grey (#121314).

Is it possible to avoid transparency on buttons in some way? I have tried to find where button color is defined, but I am not able to find it...

That's funny - I could reproduce this with all window decorations that have something black in the buttons.
This is very likely a bug. Could you please report it on bugs.kde.org (after doing a quick search to see if it's been reported before) and post the link here?

Bug report: https://bugs.kde.org/show_bug.cgi?id=218928

It seems they have already fixed this problem in 4.4...

One consideration: the search engine of bugs.kde.org does not work very well...